The invention is directed to a catheter having a basket-shaped electrode array with two or more location sensors to provide improved mapping capabilities.
Electrophysiology catheters are commonly-used for mapping electrical activity in the heart. Various electrode designs are known for different purposes. In particular, catheters having basket-shaped electrode arrays are known and described, for example, in U.S. Pat. No. 5,772,590, the disclosure of which is incorporated herein by reference.
Additionally, it is generally known to incorporate into certain electrophysiology catheters a location or position sensor for determining the location of electrodes being used to map electrical activity. Such catheters are generally inserted percutaneously and fed through one or more major blood vessels into a chamber of the heart. A location sensor in the catheter, typically near the catheter""s distal end, gives rise to signals that are used to determine the position of the device relative to a frame of reference that is fixed either externally to the body or to the heart itself. The location sensor may be active or passive and may operate by generating or receiving electrical, magnetic or ultrasonic energy fields or other suitable forms of energy known in the art.
U.S. Pat. No. 5,391,199, the disclosure of which is incorporated herein by reference, describes a position-responsive catheter comprising a miniature sensor coil contained in the catheter""s distal end. The coil generates electrical signals in response to externally-applied magnetic fields, which are produced by field-generator coils placed outside the patient""s body. The electrical signals are analyzed to determine three-dimensional coordinates of the coil.
International Publication No. WO 96/05768, the disclosure of which is also incorporated herein by reference, describes a position-responsive catheter comprising a plurality of miniature, preferably non-concentric sensor coils fixed in its distal end. As in U.S. Pat. No. 5,391,1999, electrical signals generated by these coils in response to an externally-applied magnetic field are analyzed so as to determine, for example, six-dimensional position and orientation coordinates of these coils.
Multiple position-sensing devices may be placed in a known, mutually-fixed spatial relation at or adjacent to the distal end of a catheter, as described, for example, in International Publication No. WO 97/24983, the disclosure of which is incorporated herein by reference. This publication describes a catheter having a substantially rigid structure at its distal end, to which one or more position sensors are fixed. The sensors are used to determine the position and orientation of the rigid structure.
The present invention is directed to an improved catheter having a basket-shaped electrode assembly. The basket-shaped electrode assembly can expand into a variety of positions and has two or more location sensors for determining the location of electrodes mounted on the assembly.
In one embodiment, the invention is directed to a catheter comprising an elongated catheter body having proximal and distal ends and at least one lumen therethrough. A basket-shaped electrode assembly is mounted at the distal end of the catheter body. The basket assembly has proximal and distal ends and comprises a plurality of spines connected, directly or indirectly, at their proximal and distal ends. Each spine comprises at least one electrode. The basket assembly has an expanded arrangement wherein the spines bow radially outwardly and a collapsed arrangement wherein the spines are arranged generally along the axis of the catheter body. The catheter further comprises a distal location sensor mounted at or near the distal end of the basket-shaped electrode assembly and a proximal location sensor mounted at or near the proximal end of the basket-shaped electrode assembly. In use, the coordinates of the distal location sensor relative to those of the proximal sensor can be determined and taken together with known information pertaining to the curvature of the spines of the basket-shaped mapping assembly to find the positions of the at least one electrode of each spine.